Author's note: I originally wrote this as a drabble for Tumblr but I liked it so much I decided to post it here. This story takes place entirely during the scene in S1E2 when Lucien comes home late and talks to Jean about whether or not she should stay. The song actually playing on the radio is a modern piece written in the 1940's style called "Sweetheart Swing" by Tim Garland. I chose a real 1940's song to give it historic placement.
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Lucien walked into the house, well past nine at night. He had slipped in through the sun room into the kitchen to avoid waking anyone up. The first thing he noticed was the music. Moonlight Serenade by Glen Miller was drifting through the kitchen from some other part of the the house. He marveled at the possibility that this song would be playing in his home, seemingly from nowhere. It had been one of his favorite songs once, back when he used to dance. Back when he used to have someone to dance with. Usually those memories came with unbearable pain but this time he felt wistful. He looked down at the cold dinner in front of him and felt a pang of remorse. It had been 17 years since anyone cared whether or not he was late to dinner.
He followed the sound of the soft music to the stairs that lead to Jean's room. He had decided that he really didn't need a housekeeper and that Jean aught to look for work elsewhere. He had planned to tell her in the morning. If she was still up he could do it tonight and get it over with. He walked up the stairs softly, afraid to break the spell of the music. To his surprise the door was open and he peered inside. Even alone in her room late at night she had tidy hair and was wearing a silk blouse that clung appealingly to her body. In repose, reading a book, the tense and forbidding expression she wore most of the time had faded to a serene ease. She really was a pretty little thing, Lucien thought. He suspected she was still dressed with the door open because she had been waiting up for him. It had been 17 years since anyone had cared whether or not he came home at night. He wondered if he had accidentally wandered into another man's perfect life.
For a brief moment, watching her through the door and surrounded by music, Lucien felt all his pain dissipate. The nightmares, the self loathing, the shouting in his head - he felt like it all might disappear forever if he could just stay right where he was and stretch out this other man's life indefinitely. Jean looked up from her book, slightly startled and clearly annoyed at the intrusion. She stood up to see what he wanted. Lucien asked if he could come into the room, and then asked if he could sit down. He decided, as he stepped through the door in between worlds, that he would ask her to stay.